The present invention relates to the manufacture of printing systems and methods for printing. More particularly, the present invention relates to a printing system that is configured to radially print onto a media that rotates in relation to a printing assembly.
Conventional printing systems typically utilize rectangular based bitmaps. In general, a conventional printing system prints onto a standard size rectangular-shaped media along a horizontal axis, for example, and the media is moved along a vertical axis. Typically, after the paper advances to a desired vertical location under a head assembly, the printing assembly moves across the paper to print an image onto the paper while the paper is held stationary. In sum, conventional printing systems generally implement movements within a rectangular coordinate system for printing onto media having standard sizes and shapes.
To facilitate discussion, FIG. 1 depicts a conventional printing system 10 in the form of a typical ink jet printer. As shown, the printing system 10 includes a print head 102, a roller 106, and an actuator 108. The print head 102 is configured for dispensing ink onto a print media 100, representing, for example, a rectangular sheet of paper. The actuator 108 is configured for moving the print head 102 across the print media 100. The roller 106 is configured for moving the print media 100 under the print head 102.
Typically, the roller 106 moves the print media 100 perpendicularly to the movement of the print head 102. That is, the media 100 travels under the print head 102 along a y-axis 110, and the print head moves over the media 100 along a x-axis 112.
The movements of the roller 106 and print head 102 generally occur during different time periods. For example, the roller 106 initially feeds the media 100 to an initial position under the print head 102. This initial position is typically at the top, left corner of the media 100. The roller 106 stops moving the media 100, and the media 100 is immobilized. After the media 100 stops moving, the print head 102 begins to dispense ink across the media 100 at a first y-axis position. For conventional bi-directional printers, the print head 102 moves and prints from the left side to the right side of the media. When the print head 102 reaches the right side of the media 100, the print head 102 typically stops while the roller 106 moves the media 100 to a second position along the y-axis 110. For example, when the print head 106 completes a first line, the roller 106 moves the media 100 up so that the print head 102 may then print a second line. After the roller 106 repositions the media 100, the print head 102 moves and prints from the right side to the left side of the media 100 at a second y-axis position.
Although conventional printing systems such as those described above are suitable for certain applications, they also have certain disadvantages. For example, since the print head 102, in bi-directional printers, moves and prints from left to right and then from right to left, the timing of the ink dispensement is relatively complex. That is, when the print head 102 is moving in the +x direction, ink must be dropped at a position to the left of the desired ink dispensement site on the media 100. In contrast, when the print head 102 is moving in the -x direction, ink must be dropped at a position to the right of the desired ink dispensement site on the media 100.
Also, if odd-shaped, or non-rectangular, media 100 were placed within a conventional rectangular based printer, the print head 102 and associated actuator 108 would necessarily be configured such that space was wasted. For example, for a CD-shaped media 100, the actuator 108 would have to be configured to allow printing across the full diameter of the CD. That is, the actuator 108 would necessarily move the print head across the entire diameter of the CD. In other words, the conventional printer will be configured to print within a rectangular area that encompasses the CD-shaped media. In sum, the actuator 108 of the conventional printer 100 is necessarily configured to print lines across a maximum width of the media 100. Consequently, the size of the actuator 108 in typical rectangular based printers must typically be configured to move the print head along a maximum width of the media 100.
Conventional printing systems 10 fail to provide an easy way for printing on non-standard size media, such as a label for a CD-ROM 104 shown in FIG. 1. Being circular in shape and too small and/or irregular in size to be properly handled by the paper handling system of conventional printer systems, the CD label must typically be attached in some manner to another regular-sized media (e.g., a sheet of paper) and fed as such into the conventional printer before printing can occur. Conventionally printing systems are also typically not able to handle inflexible media types, such as a CD itself, for example. Even for printers that do not require flexible media, one must typically add a special media holder for each type of non-standard media. Otherwise, the non-rectangular shape of the CD label causes difficulties in conventional printing systems, which are typically configured to handle media and print head movements in the rectangular system. Also, printing control systems (not shown), which control the movements of the print head 102, typically are not designed to direct the print head across media (e.g., 102) having variable widths along the x-axis 112, such as the circular-shaped CD label 104 of FIG. 1.
Conventional printers also fail to efficiently utilize all movements of the media 100 for printing. That is, the print head 102 stops dispensing ink onto the media 100, i.e., stops printing as the roller repositions the media 100. Thus, during operation of conventional printers, there may be a period of time during which no printing occurs.
In view of the foregoing, there is a need for an improved printing system, and more specifically, an improved printing system that efficiently implements simple movements for printing onto media having nonstandard size and shape.